The intermediate optical flows are highly uncertain, thus how to estimate accurate intermediate optical flows from the consecutive frames is a crucial problem for motion-based VFI methods. When obtaining the intermediate flow, the target image can be obtained by simple backward warping. Jiang et al. [1]} linearly combined optical flows between the input frames to approximate the intermediate flows. Bao et al. [2]} proposed a flow projection layer to reverse the optical flows between the input frames and the target frame. Xue et al. [3]} proposed a task-oriented flow estimation network to predict the intermediate flow directly. Recent VFI methods [4]}, [5]} proposed to use the distillation strategy to promote the accuracy of the intermediate flow estimation and leads to large performance improvement. Inspired by these works, our method jointly uses the distillation strategy and the task-oriented flow estimation strategy to predict the intermediate flow in a coarse-to-fine manner.
